As a core technology in modern manufacturing, advanced motion control systems have received considerable attention in the past decades. Motion control is a fundamental concern in many industrial applications. For example, putting an object in the correct place with the right amount of force at the right time is essential for efficient manufacturing operations. High speed and high accuracy positioning systems are essential elements in advanced manufacturing systems such as semiconductor industry (e.g. Surface Mounting Technology-SMT). The demands for higher productivity and quality call for the development of high performance positioning devices. Motion control is widely used in modern manufacturing and becomes one of the technological foundations of industrial automation. At present time, more and more manufacturing companies are looking forward to applying multi-axis motion control architecture in their machinery designs and production lines. This is not only for rapid production, but also for accuracy requirement in so many missions in which multi-axis motions must be performed synchronously.
System design plays a critical role in overall performance of the motion control system. Since the sampling frequency of the motor control loop is usually considered as an important criterion for evaluating a good motion control system, the use of high-frequency motion control and driving systems is becoming the trend. The low frequency characteristic degrades the performance significantly, even though an advanced control algorithm is used. On the other hand, traditionally, the motion control card is inserted inside a PC so that the CPU of the computer can be utilized. Such architecture is not ideal to industrial environments. Applying a distributed architecture in motion control design, in which the control system is separated physically from the computer and does not rely on the computer's CPU, is an ideal solution to improve overall performance (including increment of sampling frequency). Employing a distributed motion control system is becoming hot in recent years. With a distributed architecture, the control system employs its own CPU by Digital Signal Processor (DSP) technology, and runs in high speed. Through RS232/RS485 communication, the distributed control system can be connected with the computer for various interface operations.
Another possible solution to improve overall system performance is to integrate motion control and driving system together, since a good motion system must be able to handle control and driving simultaneously. An integrated design of outer position loop and inner current loop with digital technologies will help optimize the overall design, and more importantly, allow the use of high-speed communication buses.
Therefore, there is a need to provide a new control and driving system that makes it possible to design high-frequency control loops and the dimension of the system is reduced to a great extent.